Best class to carry?

So my friends started playing WoW and while they do have some experience in PvP, they really suck in arenas. So I have been playing a warrior so far but there is only so much you can do as a warrior. My question is which class do you think would be able to carry in 3s better? Leaning towards mage or druid or perhaps rogue with the new 5.1 changes?

Resto Shaman / Warlock can carry any comp really. (From personal experience I had all classes at 85 and my main is a 90 Monk now and I will say when I played Resto Shaman / Warlock I felt like I could influence the game most).

Well, I'm afraid resto lock is no longer the top combination.
While warlocks still have a good synergy with healers, the synergy is no longer that strong as it was in tbc and cata.

Not only that, but affliction warlocks were very strong in arena due the good pressure they had, but now with the changes to affliction and with how malefic graps is required to do a lot of damage with dots, affliction is nothing more than a weaker shadowpriest with a spamable fear and a better dispelprotection.

Now to stay on topic, rogues currently aren't doing to amazing compared to other melee, but it wouldn't surprise me if they become the top melee in 5.3-5.4 due how they scale.
As for mage, mages currently have 2 very good specs for arena and will high likely be a topclass for the rest of the expansion.
Druids on the other hand are currently amazing healers, however, balance and feral are really lacking right now but that might change.

Well, I'm afraid resto lock is no longer the top combination.
While warlocks still have a good synergy with healers, the synergy is no longer that strong as it was in tbc and cata.

Not only that, but affliction warlocks were very strong in arena due the good pressure they had, but now with the changes to affliction and with how malefic graps is required to do a lot of damage with dots, affliction is nothing more than a weaker shadowpriest with a spamable fear and a better dispelprotection.

Now to stay on topic, rogues currently aren't doing to amazing compared to other melee, but it wouldn't surprise me if they become the top melee in 5.3-5.4 due how they scale.
As for mage, mages currently have 2 very good specs for arena and will high likely be a topclass for the rest of the expansion.
Druids on the other hand are currently amazing healers, however, balance and feral are really lacking right now but that might change.

What the heck? Hunters have been nerfed (or fixed how ever you want to look at it) to a point where they're only average. Kittycleave is definitely the best comp at the moment.

On topic, stick to warrior, they can carry.

Warrior can carry only if you severely outgear your opponent which mens just outdps them. I find myself unable to do more with the class at some points just because warriors don't have high enough skillcap. I need some class that would let me (if played well) to not rely on other teammates that much to make things happen. For example my buddy will help me kill the target, but he ain't good enough to set up the kill on his own or if I shall be a healer I have to be able to setup that aswell and only expect raw damage with an interrupt here and there from my teammates.

I'm not saying they are bad, they just can't compete with the whole hunter/warrior game that is going on currently so I can't really tell how good they'll be in 5.1

Kittycleave is better than current Kfc. Ferals are the second best melee atm, right behind warriors.

On topic.. Mage, warrior, feral, demo lock, resto druid. All of them are getting hugely rewarded for outplaying the opponent.. I wouldn't play 2s btw unless you are planning to play double dps. But in general any double dps team, except for probably double melee, are a bit underpowered against most healer/dps teams, solely because of how strong healers are at the moment

In my experience trying to carry someone who is crap at PvP will get old very quickly, unless you have the patience of a saint. I'm helping my nephew cap his conquest points, but when the only thing he uses is obliterate and frost strike, it gets difficult. I can't imagine trying to get any sort of rating.

Mage has a good bit on control on all classes via Rings, Poly, Novas and CS and some insane damage on deeps.
Warlock can put out some crazy instant CC because of Bloodfear, their self-heals are pretty good and damage can be insane if played right.

For mage and lock? Any other DPS really, so long as they have the ability to CC and/or put out a bit of damage inside of the other class' cooldowns. You can run healer/DPS with either class but I simply don't find that fun and it can lead to long games if you're paired against an equally skilled (or simply unkillable) healer/dps team.

I don't see many locks in 2s but the better mage teams I've seen have been:
Mage/Spriest
Mage/Feral
Mage/Warrior

I played spriest/mage last week with my mage friend on my undergeared spriest (still 5 pieces of Cataclysmic) and so long as I was able to live and heal/CC for him when needed we won vs most setups.

I know people throw around this word a lot but if you have good synergy with a person from playing with them a lot it doesn't really matter what class you're each playing, you know how the other is going to react to a situation after a while and it becomes easier even if you're running an obscure comp.